Return of revitalised Montero

Jefferson Montero (left) was superb in the first half, seeing plenty of the ball and regularly getting into advanced positions near the byeline. By contrast his Chelsea counterpart Pedro (right) was peripheral, with most of his touches coming in his own half

Starting the match 10 points above the bottom three and with survival all but guaranteed, the Swans selected a more attacking team with Jefferson Montero the orchestrator of a vibrant team display.

With injury and a loss of form curbing his progress after a sparkling start to the season, the Ecuadorian winger was making his first start under Guidolin.

Montero probed menacingly at Chelsea's defence and created the game's first chance for Sigurdsson, whose firm shot was palmed away by Asmir Begovic.

It was the same formula which produced the opening goal, as Montero's cross was only half-cleared into the path of Sigurdsson, who guided a left-footed volley into the bottom corner.

Montero ran relentlessly on Swansea's left flank, as Chelsea defenders Cesar Azpilicueta and Matt Miazga were both booked for fouls on the 26-year-old.

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Miazga was substituted at half-time, and Chelsea were fortunate not to be further behind at the break as Sigurdsson and Andre Ayew both had shots saved by Begovic.

It was a ragged display from the visitors, who were playing their first game since confirming Italy manager Antonio Conte would take over at Stamford Bridge after Euro 2016.

The former Juventus boss is likely to have been unimpressed by Chelsea's sloppy defending in south Wales, while their efforts in attack left much to be desired.

Brazilian forward Alexandre Pato was underwhelming on his first start, looking short of match fitness and squandering two promising chances.

Chelsea began to control possession as the match wore on, with Swansea dropping deep as they sensed a precious win was within their grasp.

Despite keeping the ball for long periods, however, Chelsea seldom troubled Lukasz Fabianski in the home goal.

Man of the match - Jefferson Montero

The Swansea winger was outstanding, delivering 10 crosses from open play and also making four tackles, a team high

What they said

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Guidolin 'very proud' after Chelsea win

Swansea manager Francesco Guidolin: "This is the first victory in the Premier League for Swansea against Chelsea and I am happy and proud. We played very well in the first half, we deserved to score other goals.

"It's a very important win for our fans. It's a good afternoon for our players, our club and our fans. Jefferson Montero is an important player for us. Safety is almost real, but I hope to take other points in the next weeks because it's important to finish well."

Chelsea manager Guus Hiddink: "Every defeat hurts but everyone knows the situation we are in, so there's a positive side to bringing in youngsters and seeing what they can do. We defended poorly and gave Sigurdsson a very free chance. We were attacking, attacking, but in the final third we were not sharp enough."

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Chelsea were not strong enough - Hiddink

The stats you need to know

Combined with his first spell at Chelsea, it was only Guus Hiddink's second loss in the Premier League (W17 D9).

Only Harry Kane (11) and Sergio Aguero (10) have scored more Premier League goals in 2016 than Gylfi Sigurdsson.

Swansea's past six home league games have produced just seven goals, with no side scoring more than once in any of those fixtures.

The Swans have won three consecutive Premier League home games for the first time since March 2013.

Chelsea have failed to win away from home when Asmir Begovic has played in the Premier League this season (D2 L5).

What's next?

Chelsea host Manchester City on April 16 as they bid to hang on to their top-half status, while Swansea visit relegation-threatened Newcastle on the same day.